Use the angle subtraction formula for cosine.

March 29, 2026Mathematics

ScanSolve AI Answer

March 29, 2026

Answer

\cos A \cos B + \sin A \sin B $$

Q.2 (i) Find the value of $\cos 15^\circ$ .

Step 1: Use the angle subtraction formula for cosine. $\cos(A - B) = \cos A \cos B + \sin A \sin B$ Let $A = 45^\circ$ and $B = 30^\circ$ .

Step 2: Substitute the values of $A$ and $B$ . $\cos 15^\circ = \cos(45^\circ - 30^\circ) = \cos 45^\circ \cos 30^\circ + \sin 45^\circ \sin 30^\circ$

Step 3: Substitute the known trigonometric values.

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Q.2 (i) Find the value of 15^. Step 1: Use the angle subtraction formula for cosine.

Asked on March 29, 2026Mathematics

This mathematics problem involves applying core mathematical principles and formulas. Below you will find a complete step-by-step solution with detailed explanations for each step, helping you understand not just the answer but the method behind it.

ScanSolve AI AnswerAnswered on March 29, 2026

Q.2 (i) Find the value of 15^. Step 1: Use the angle subtraction formula for cosine. (A - B) = A B + A B Let A = 45^ and B = 30^. Step 2: Substitute the values of A and B. 15^ = (45^ - 30^) = 45^ 30^ + 45^ 30^ Step 3: Substitute the known trigonometric values.